The statements in this section merely provide background information related to the present disclosure and may or may not constitute prior art.
Transmission oil pumps are typically mounted to the transmission case above the oil fill level and are driven by a separate electric motor, such as a permanent magnet type motor. The transmission oil pump requires a relatively high starting torque from the motor, especially in colder temperatures (usually less than about −25° C.). Sometimes the motor is unable to provide the required starting torque, which results in the transmission oil pump stalling.
In addition, typical transmission oil pumps include a hydraulic passage, such as a suction tube, that is used to deliver oil from an oil pan to the transmission oil pump. However, several issues may arise when employing a suction tube to deliver oil to the transmission oil pump. For example, the suction tube is typically sealed by an O-ring which can fail, causing an oil leak. Moreover, because the transmission oil pump is located above the oil fill level of the transmission, cavitation may occur in the suction tubes during high flow rates, and the priming time of the oil pump may be increased.
Accordingly, while current transmission oil pumps achieve their intended purpose, there is a need for a new and improved transmission oil pump which exhibits improved performance from the standpoints of improved starting torque, reduced cavitation, and reduced leakage.